Spring loaded butt contact with external contacting sleeve



Dec. 20, 1955 c. w. KLOSTERMANN 2,728,062

SPRING LOADED BUTT CONTACT WITH EXTERNAL CONTACTING SLEEVE Filed Dec. 4,1952 K r yll ii INVENTOR.

United States Patent Ofilice 2,728,062 Patented Dec. 20, 1955 SPRINGLOADED BUTT CONTACT WITH EXTERNAL CONTACTING SLEET.

This invention relates to electrical contacts and, more particularly, toa specific form of butt-type contacts known in the trade as pressurecontacts. These are distinguished from other contact types in that theconnecting elements do not telescope within each other as is cus tomaryin the art, but are held in abutting engagement with each other by apressure spring.

It is the general aim of the invention to provide a spring loadedcontact assembly having an exterior housing and a main conducting memberjoined to its conductor, with an internal sliding contact plunger whichis capable of accomplishing smooth, positive sliding move ment of acontact plunger with respect to the conducting member, while maintaininga low electrical resistance between the plunger and parts within whichit slides.

A further object of the invention is the provision of a pressure typecontact including a longitudinally spring urged plunger wherein theassembly includes means for limiting the compression of the spring, sothat the spring will not be flexed beyond its elastic limit and cannotbe easily distorted by excessive thrusts applied to the contact plunger.

7 Another important object is to provide a spring urged contact whereinthe pressure spring utilized therewith does not form a part of theelectrical circuit. This avoids unwanted inductive elrects due to thecoils of the spring, and prevents damage to the s ring by overheating byelectrical overload.

It is a still further object of the invention to provide produced bymass production methods or" manufacture.

These objects are accomplished according to the present teaching by theprovision of a contact housing ar ranged to be secured within theinsulated dielectric of an electrical connector and provided with a mainconducting member having an annular spring collet held in the hou: ingadjacent the rear end thereof, with a plurality of yieldable spring jawsextending forwardly v housin sleeve and biased inwardly to engage the exterior cylindrical surface of a spring urged contact plunger in thecollet bore. In the preferred form of the invention the collet isprovided with a tapered mouth and an enlarged internal cavity behind thejaw portions to coact with an annular collar on the plunger, so that theparts may be assembled simply by pressing the plunger into the collet,which will snap the plunger in place to retain it against removal. Thearrangement is such that expansion of the collet is limited by itsexterior housing so that the jaws of the collet cannot be flexedoutwardly sufiiciently to distort them. Also, if desired, the exteriorhousing may be fitted so that when the plunger is once assembled in thecollet, they cannot be disassembled without entirely dismantling thedevice.

As shown, the plunger is urged longitudinally by a relatively small coilspring housed entirely within the plunger and so arranged that theplunger itself forms a limiting stop to prevent excessive thrusts on theplunger from damaging the spring.

A preferred embodiment of the invention is illustrated in the drawingsof this specification, wherein:

Figure l is a central sectional view of a contact asment with a matingcontact;

Figure 2 is a detail sectional view taken substantially on the plane ofthe line 22 of Figure l; and

Figure 3 is a perspective view of the main conducting member of theassembly.

The novelty of the present invention resides in the pressure contactassembly generally designated as 10, which may be mounted in thedielectric insert 11 of a connector shell to be held in contactingengagement with the forward face 12 of a mating contact 13 mounted in anopposite dielectric member 14.

The pressure contact assembly member 10 includes a main conductingmember 35 (Figure 3) mounted within a sleeve-like housing 16 and securedto the dielectric insert 11 by a threaded collar or coupling ring 17.The main conducting member 15 includes an enlarged central flange 21with a tubular portion 22 extending rearwardly therefrom and cut away at23 to provide a soldering pocket 24 in which a flexible conductor may besecured. The forward portion 25 of the main conducting member is oftubular configuration, but is slotted at 26 to provide a plurality ofseparate, resilient jaws 27 which coact to form a collet having arcuateinner slide surfaces 28 at the forward end thereof.

As shown, the forward end of each of the collet jaws 1S tapered asindicated at 29 to facilitate the entrance of a contact slide plungergenerally designated as 31. The plunger 31 includes a projecting head orcontact portion 32 adapted to engage the face 12 of the mating contact13, and a tubular rear portion 33 having an internal bore 34 in which asmall helical coiled compression spring 35 is positioned. The plungerhas an enlarged collar 36 intermediate the portions 32 and 33, and thecollar is preferably tapered at 37 so that the surfaces 37 and 2? willcoact to spread the collet jaws 27 as the plunger is pressed into place.The internal bore of the collet is undercut at 38, however, to provide areverse shoulder 39 which engages the enlarged collar 31, to limittheoutward movement of the plunger. Thus, the plunger 31 and spring 35may be assembled by merely inserting them in the collet and snappingthem into place, after which they are self-retaining.

With this arrangement, it will be seen that the plunger head 32. is heldin snug sliding contact within the collet jaws, but is free to moveinwardly and outwardly within the limits provided by the shoulder 39 ofthe undercut 33-; and engagement of the rear portion of the sleeve 34with the bottom of the collet bore. The jaws of the collet includeindividual arcuate friction or wiping contacts which lie insurface-to-surface contact with the plunger head 32 in a location closeto the point of engagement between the contact 32 and the mating contactface 12. This not only provides an intimate electrical union between thestationary and movable parts of the assembly, but also provides adequatemetal around the contact to eiiectively dissipate any heat produced bythe passage of electrical current therethrough. The coacting parts ofthe entire assembly are of heavy, rugged construction and thus are ableto withstand considerable mechanical abuse as well as having the abilityto withstand considerable electrical I; t I 2,728,062

surrounds the collet jaws 27 sufficiently closely to limit outwardflexing of the jaws, and thus prevents the jaws from being distorted tothe point where they exceed their elastic limit and lose theirresiliency.

Having thus described my invention, what i claim as new and desire tosecure by United States Patent is:

1. In an electrical connector, a mounting sleeve adapted to be securedwithin a dielectric insert, said sleeve having a cylindrical boreextending therethrough and having a screw threaded rear end portionprojecting from the insert, with a retaining cap threaded thereon; amain conducting member held within said mounting sleeve, said mainconductor having an enlarged flange intermediate its ends and secured tothe rear end of the mounting sleeve by said threaded cap, the mainconducting member including a tubular solder pocket portion extendingrearwardly from said cap and a forward portion of generally tubularconformation with a plurality of longitudinal slots therein dividing theforward portion into a plurality of collet jaws, the exterior surface ofsaid collet jaws being substantially cylindrical and spaced nwardly ofbut close to the cylindrical bore of the mounting sleeve, said colletjaws having an internal slide bore flared at the forward end thereof andhaving an enlarged undercut at a point intermediate the ends of saidjaws; a contact plunger having a cylindrical head portion in slidingengagement with the forward ends of the collet jaws, with an annularcollar intermediate the ends of the plunger adapted for limitedlongitudinal movement in the undercut portions of said collet jaws, anda central bore extending into said plunger from the rear end thereof,with a coiled compression spring housed within said bore and bearingagainst the main conducting member to urge the plunger forwardlytherefrom.

2. In an electrical connector, a mounting sleeve adapted to be securedwithin a dielectric insert, said sleeve having a cylindrical boreextending therethrough with a main conducting member held within saidmounting sleeve and secured to the rear end of the mounting sleeve; themain conducting member including a tubular solder pocket portionextending rearwardly from said cap and a forward portion of generallytubular conformation with a plurality of longitudinal slots thereindividing the forward portion into a plurality of collet jaws, theexterior surface of said collet jaws being spaced inwardly of but closeto the cylindrical bore of the mounting sleeve, said collet jaws havingan internal slide bore and having an enlarged undercut at a pointintermediate the ends of said jaws; a contact plunger having acylindrical head portion in sliding engagement with the forward ends ofthe collet jaws, with an annular collar intermediate the ends of theplunger adapted for limited longitudinal movement in the undercutportions of said collet jaws, and a central bore extending into saidplunger from the rear end thereof, with a coiled compression springhoused within said bore and bearing against the main conducting memberto urge the plunger forwardly therefrom.

3. In an electrical connector, a mounting sleeve adapted to be securedwithin a dielectric insert, said sleeve having a cylindrical boreextending therethrough and having a screw threaded rear end portionprojecting from the insert with a retaining cap threaded thereon; a mainconducting member held within said mounting sleeve, said main conductorhaving an enlarged flange intermediate its ends and secured to the rearend of the mounting sleeve by said threaded cap, the main conductingmember including a tubular solder pocket portion extending rearwardlyfrom said cap and a forward portion of generally tubular conformationwith a plurality of longitudinal slots therein dividing the forwardportion into a plurality of collet jaws, the exterior surface of saidcollet jaws being substantially cylindrical and spaced inwardly of butclose to the cylindrical bore of the mounting sleeve, said collet jawshaving an internal slide bore flared at the forward end thereof; acontact plunger having a cylindrical head portion in sliding engagementwith the forward ends of the collet jaws, with a bore extending intosaid plunger from the rear end thereof; a coiled compression springhoused within said bore and bearing against the main conducting memberto urge the plunger forwardly therefrom, and means to limit the forwardmovement of the plunger.

4. In an electrical connector, a mounting sleeve adapted to be securedwithin a dielectric insert, said sleeve having a cylindrical boreextending therethrough with a main conducting member held within saidmounting sleeve and secured to the rear end of the mounting sleeve; themain conducting member including a tubular solder pocket portionextending rearwardly from said cap and a forward portion of generallytubular conformation with a plurality of longitudinal slots thereindividing the forward portion into a plurality of collet jaws, theexterior surface of said collet jaws being spaced inwardly of but closeto the cylindrical bore of the mounting sleeve, said collet jaws havingan internal slide bore with a contact plunger having a cylindrical headportion in sliding engagement with the forward ends of the collet aws,with a bore extending into said plunger from the rear end thereof; acoiled compression spring housed within said bore and bearing againstthe main conducting member to urge the plunger forwardly therefrom, andmeans to limit the forward movement of the plunger.

References Cited in the file of this patent UNITED STATES PATENTS

